Bug 466326 - System hangs when unplugging/plugging in multiple monitors or enabling/disabling displays in settings
Summary: System hangs when unplugging/plugging in multiple monitors or enabling/disabl...
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: multi-screen (show other bugs)
Version: 5.27.0
Platform: NixOS Linux
: NOR major
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: multiscreen
Depends on:
Blocks:
 
Reported: 2023-02-24 01:40 UTC by Brian Tipton
Modified: 2024-07-29 21:58 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
GDB (37.81 KB, text/plain)
2023-02-26 06:25 UTC, Brian Tipton
Details
Diagnosis Info (7.11 KB, text/plain)
2023-02-26 06:25 UTC, Brian Tipton
Details

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Description Brian Tipton 2023-02-24 01:40:46 UTC
SUMMARY
***
NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols.
See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports
***


STEPS TO REPRODUCE
1. Hot swap monitor with a KVM like device or enabling/disabling a monitor in settings
2. 
3. 

OBSERVED RESULT
System hangs and a hard reboot is needed to get back to a working state. Sometimes can get to a TTY by CTRL-ALT-F1

EXPECTED RESULT
Disabling or enabling monitors as needed

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma:
(available in About System)
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Comment 1 Nate Graham 2023-02-24 20:16:31 UTC
If something crashed, we need a backtrace of it so we can figure out what's going on. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports.

Can you please attach one? Thanks!
Comment 2 Brian Tipton 2023-02-26 06:24:34 UTC
(In reply to Nate Graham from comment #1)
> If something crashed, we need a backtrace of it so we can figure out what's
> going on. See
> https://community.kde.org/Guidelines_and_HOWTOs/Debugging/
> How_to_create_useful_crash_reports.
> 
> Can you please attach one? Thanks!

Yea sorry, I meant to post one the other night.  Another couple thing to note, I have 2 GPU's attached to my machine with VFIO setup. Whenever I swap the monitors via KVM I am swapping to the output of the 2nd GPU. The swapping seems to be okay when removing monitors, but when I am attempting to reconnect the monitors via KVM the system gets very laggy on the running monitor (mouse/windows visually jumping around). Then when I go inside the system settings to disable/enable to attempt to get them to work it crashes. Also tested on 5.27.1 with same results.  I will also attach diagnosis info. Thanks
Comment 3 Brian Tipton 2023-02-26 06:25:13 UTC
Created attachment 156743 [details]
GDB
Comment 4 Brian Tipton 2023-02-26 06:25:30 UTC
Created attachment 156744 [details]
Diagnosis Info
Comment 5 Nate Graham 2023-02-27 16:50:54 UTC
The gdb backtrace doesn't show that kwin_wayland crashed but rather than it was interrupted.

Can you get a backtrace of the crash itself?
Comment 6 Brian Tipton 2023-02-27 21:15:41 UTC
(In reply to Nate Graham from comment #5)
> The gdb backtrace doesn't show that kwin_wayland crashed but rather than it
> was interrupted.
> 
> Can you get a backtrace of the crash itself?

This gdb was during the "crash", I didn't realize it wasn't actually crashing the kwin process.
Comment 7 Brian Tipton 2023-02-27 21:19:24 UTC
It (In reply to Nate Graham from comment #5)
> The gdb backtrace doesn't show that kwin_wayland crashed but rather than it
> was interrupted.
> 
> Can you get a backtrace of the crash itself?

(In reply to Brian Tipton from comment #6)
> (In reply to Nate Graham from comment #5)
> > The gdb backtrace doesn't show that kwin_wayland crashed but rather than it
> > was interrupted.
> > 
> > Can you get a backtrace of the crash itself?
> 
> This gdb was during the "crash", I didn't realize it wasn't actually
> crashing the kwin process.


(In reply to Brian Tipton from comment #6)
> (In reply to Nate Graham from comment #5)
> > The gdb backtrace doesn't show that kwin_wayland crashed but rather than it
> > was interrupted.
> > 
> > Can you get a backtrace of the crash itself?
> 
> This gdb was during the "crash", I didn't realize it wasn't actually
> crashing the kwin process.

What I see on my side during the "crash" is that the cursor doesn't have the ability to move, the keyboard doesn't do anything except sometimes lets me get to a TTY. And windows seems to be stuck at there last position. Most of the time it requires a reboot to get out of this state
Comment 8 Nate Graham 2023-02-28 17:05:28 UTC
Ah, that's not a crash. :) That's a hang.